We have analyzed human centromeric chromatin containing CENPA from HeLa cells in culture using Chromatin IP followed by atomic force microscopy measurements and mass spectrophotometry. Thus far, we have identified that the CENPA chromatin structure is uniquely organized during interphase, and has fundamentally different characteristics from the rest of the chromatin which packages the genome. WE have computationally modeled CENP-A/H4 in the nucleosome and the dimer state, and demonstrated the flexiblity arises from the core of the nucleosome, causing the DNA to be very accessible. WE have performed magnetic tweezer experiments with collaborators, showing that CENP-A nucleosomes cannot withstand substantial more force than canonical nucleosomes, regardless of DNA sequence, suggesting other epigenetic features are required for centromere stability.